Apple’s big announcement is almost here. The third-generation of the popular device will finally be announced. Supplies have been constrained on the 2nd gen version, so it’s inevitable. The new one will be faster, and will support much higher resolution than its predecessor did. Gosh, I can’t wait for the new Apple TV.

No, the iPad 3 (or iPad HD?) isn’t likely to be the only new Apple product announced this month. The Apple TV (the set-top box, not the rumored TV set) is due for a refresh, and we could very well hear about it at tomorrow’s iPad event.

Rumors about an updated Apple TV have been floating around for months, but now things are getting serious. So serious, in fact, that all but a few Apple Stores are completely out of stock of the 2nd generation of the device. When this happens, there are only two possible explanations: there is either a mad rush on the product and Apple can’t keep up, or there is an imminent update. This case is an example of the latter.

If we see the Apple TV at tomorrow’s update, then you can expect to see Airplay and iCloud take center stage. After all, they’re the glue that connects the iPad with the Apple TV. In advance of the iTV (next year, perhaps?) this will help Apple to drum up interest in the set-top box, and prepare customers for Apple playing a part in their living rooms.

As for specs, you can expect to see a faster processor. Will it have the same chip as the new iPad, or something else? Recent rumors pointed to Apple making both a quad-core A6 chip and an upgraded dual-core SoC, called the A5X. Could the A6 be for the iPad, and the A5X for the Apple TV? It’s possible.

Either way, the upgraded chip (the 2nd gen Apple TV runs the two-year-old A4) will help the Apple TV to finally play 1080p content. If the Apple TV is unveiled at tomorrow’s event, then you can expect to hear “1080p” mentioned more than once. The iPad’s Retina Display will play 1080p video, the Apple TV will play 1080p video, and AirPlay will let you watch all of the iPad’s 1080p brilliance on your 52-inch flatscreen.

It’s possible that we’ll see a separate event for the Apple TV, but don’t be shocked if Apple tells us all about it at around 10am PST tomorrow morning.